(1) Field of the Invention
The present invention relates to an information reproducing apparatus and an information reproducing method capable of reading information recorded on an optical disk without an error.
(2) Description of the Related Art
For accurate reproduction of information from an optical disk, not only information on identification of read data but also information on the position (address) thereof should be correct. When user data is recorded in each block on a digital versatile disk (DVD) or Blu-Ray disk (BD), information on the address (position) of the block is also recorded. When data is reproduced from a recorded block, an address (DID) specified in the recorded data is referenced in order to check whether the address of the block is correct. No problem therefore takes place. However, when no data is recorded in a block, an address (DID) is also left unrecorded. The address cannot therefore be referenced. For identifying an address of an unrecorded area on an optical disk, technologies described below are adaptable.
(1) For the DVD±R/RW formats, there is a technology for managing the positions of blocks on an optical disk, which have data left unrecorded, using an unrecorded block management area on the disk. When a disk drive is instructed an address, from which information is reproduced, by a host, the disk drive references management information so as to decide whether the instructed block has data recorded or left unrecorded (refer to, for example, Japanese Patent Laid-Open No. H9-288883).
(2) For the DVD-RAM format, pre-pits that represent an address are formed in an optical disk in advance. When an address reading ability is improved, even the address of an unrecorded block can be correctly read by checking the pre-pits (refer to, for example, Japanese Patent Laid-Open No. 2001-297445).
(3) For the DVD±R/RW formats and BD-R/RE formats, address information is recorded by forming a wobbling groove in a disk so that the address of each block can be learned even with data left unrecorded (refer to, for example, Japanese Patent Laid-Open No. 2001-266486).